Related papers: Photon Structure Functions from Quenched Lattice Q…
On the grounds of extension of the U-matrix unitarization to the off-shell scattering we consider virtual-photon induced scattering. We discuss behavior of the structure function F_2(x,Q^2) at low x and the total cross-section of…
We compare the chemical potential associated with the onset of non-zero baryon number density on $6^4$ and $8^4$ lattices at $\beta=5.1$ and ma=0.01. We provide evidence for $Z(3)$ tunnelling. We determine a critical chemical potential of…
We present preliminary results on the proton spin structure function at zero momentum, in the quenched approximation. Our calculation makes use of a nonperturbative means of determining the multiplicative renormalization of the topological…
We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the consistently O(a) improved current. We calculate the pion form…
The polarized photon structure is described by two spin structure functions $g_1^\gamma$ and $g_2^\gamma$ which can be studied in the future polarized ep or e$^+$e$^-$ colliders. Here we investigate the QCD twist-3 effects in $g_2^\gamma$…
We calculate the leading-order matrix element for the decay $B \to K^* \gamma$ in the quenched approximation of lattice QCD on a $24^3 \times 48$ lattice at $\beta=6.2$, using an O(a)-improved fermion action. Extrapolating the quark masses…
We formulate lattice QCD in rotating frames to study the physics of QCD matter under rotation. We construct the lattice QCD action with the rotational metric and apply it to the Monte Carlo simulation. As the first application, we calculate…
We study the $Q^2$ variation of the first moment of the nucleon's spin-dependent structure function $G_1$. As $Q^2 \rightarrow 0$ the moment is determined by the low energy theorem for Compton scattering. In the deep-inelastic region the…
Using a multistate smearing method, Coulomb gauge wave functions of heavy-light mesons are studied in lattice QCD. Wave functions for the ground state, the first radially excited S-wave state, and the lowest P-wave states of a heavy-light…
The theoretical framework for a next-to-leading order QCD analysis of the spin-dependent parton densities Delta f^{gamma}(x,Q^2) of the longitudinally polarized photon and of its structure function g_1^{gamma}(x,Q^2) is reviewed in some…
We compute the electromagnetic form factors of the nucleon in quenched lattice QCD, using non-perturbatively improved Wilson fermions, and compare the results with phenomenology and chiral effective field theory.
We calculate the long-distance matrix elements for the decays of the lowest-lying S- and P-wave states of charmonium and bottomonium in quenched lattice QCD, using a nonrelativistic formulation for the heavy quarks. (The short-distance…
The theoretical description of photon production at particle colliders combines direct photon radiation and fragmentation processes, which can not be separated from each other for definitions of photon isolation used in experimental…
In this contribution we discuss recent measurements by the LEP experiments on photon structure functions.
The photo-production of nucleon resonances is calculated based on a chiral constituent quark model including both relativistic corrections H{rel} and two-body exchange currents, and it is shown that these effects play an important role. We…
Results for nucleon matrix elements (arising from moments of structure functions) and form factors from a mixture of runs using Wilson, clover and overlap fermions (both quenched and unquenched) are presented and compared in an effort to…
Lattice QCD calculations of hadron structure are a valuable complement to many experimental programs as well as an indispensable tool to understand the dynamics of QCD. I present a focused review of a few representative topics chosen to…
We study the correction to the radiative $\pi^0$ decay width due to finite light quark mass. Using lattice QCD with the overlap fermion formulation, we calculate the three-point function of the form $<PV_\mu V_\nu>$ in the (Euclidean)…
The $n$-th moments of the nuclear structure function $F_2^A(x,Q^2)$ are analyzed using the off-shell kinematics appropriate to describe deep inelastic electron-nucleus scattering within the impulse approximation. It is shown that off-shell…
We study the hadronic spectrum in quenched lattice QCD using an improved Wilson fermion action (Hamber-Wu(1983),Eguchi-Kawamoto(1984)) at $\beta= 5.7$ and $\beta =6.0$. We find a systematic reduction of the finite spacing effects compared…